Do ETFs Increase the Commonality of their Underlying Assets? Evidence from a Switch in ETF Replication Technique
Résumé
We investigate the impact of Exchange-Traded Funds (ETFs) on the comovements of their constituent securities using a novel identication that exploits the switch from synthetic to physical replication of a large French ETF. After the switch, constituent stocks experience greater commonality, in both returns and liquidity. For both the full sample of ETF constituents and the least liquid ETF constituents, a larger part of the variation in individual stock returns or liquidity is explained by market-wide variations. We present evidence that ETF creation and redemption is the transmission mechanism of the comovements. Moreover, we show that the comovements do not appear excessive.